We used fully cosmological, high resolution N-body + SPH simulations to follow the formation of disk galaxies with a rotational velocity between 140 and 280 Km/sec in a Lambda CDM universe. The simulations include gas cooling, star formation, the effects of a uniform UV background and a physically motivated description of feedback from supernovae. The host dark matter halos have a spin and last major merger redshift typical of galaxy sized halos as measured in recent large scale N-Body simulations. Galaxies formed rotationally supported disks with realistic exponential scale lengths and fall on the I-band and baryonic Tully Fisher relations. The combination of UV background and SN feedback drastically reduced the number of visible satellites orbiting inside a Milky Way sized halo, bringing it fair agreement with observations. Feedback delays SF in small galaxies and more massive ones contain older stellar populations. The current star formation rates as a function of galaxy stellar mass are in good agreement with those measured by the SDSS.
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机译:我们使用了完全宇宙学的高分辨率N体+ SPH模拟,以跟踪Lambda CDM宇宙中旋转速度在140至280 Km / sec之间的盘状星系。模拟包括气体冷却,恒星形成,统一的紫外线背景的影响以及对超新星反馈的物理描述。主机暗物质光环具有自旋和最后一次主要合并红移,这是最近大规模N体模拟中测得的星系大小光环的典型特征。星系形成了旋转支撑的圆盘,具有现实的指数尺度长度,并且落在I波段和重质塔利费舍尔关系上。紫外线背景和SN反馈的结合极大地减少了在银河系大小的光晕内部绕行的可见卫星的数量,这使其与观测值完全吻合。反馈会延迟小星系中的SF,而更大的星系中则包含较旧的恒星族。当前的恒星形成率与星系恒星质量的函数与由SDSS测量的结果非常吻合。
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